The invention relates generally to safety line latching apparatus for use with vehicle towing systems. More specifically, the invention concerns such apparatus for use with towing systems wherein the towed vehicle is lifted and towed principally by its wheels, and the latching apparatus retains a safety line, such as a chain, in a taut towing condition.
The concept of using detachable, inwardly facing L-shaped wheel cradles in a wheel lift towing system was first introduced in U.S. Pat. No. 4,679,978-Holmes et al., assigned to the same assignee as this invention. So-called "wheel lift" towing approaches avoid the need for the conventional tow truck sling assembly by using wheel engaging structures or "wheel cradles" which engage the front or rear wheels of a vehicle to be towed to lift the wheels and therefore one end of the vehicle substantially without engaging any other portion of the vehicle. The '978-Holmes et al. patent disclosed such a wheel lift tow assembly mounted to the frame at the rear of a tow vehicle and moveable vertically. The two assembly of the Holmes et al. disclosure included a telescopic tow bar extended and retracted from the rear of the vehicle and a cross arm pivotally mounted intermediate its ends about an upwardly extending axis to a rear portion of the telescopic tow bar. L-shaped wheel cradles were releasably connected to end portions of the cross arm in the Holmes et al. patent.
The present invention is for use with safety lines, such as chains, used in conjunction with wheel lift systems which do not employ straps or belts securing the towed wheel to its associated wheel cradle. One such beltless wheel lift arrangement is disclosed in a co-pending application to Holmes et al., filed of even date herewith and entitled QUICK CONNECT/DISCONNECT WHEEL CRADLE ARRANGEMENT FOR WHEEL LIFT TOWING SYSTEMS.